Lighting systems are known to consume a large proportion of energy in buildings and more generally in city infrastructures, see, for example, Energy Information Administration, “Commercial Buildings Energy Consumption Survey,” 2003. As known, an intensive operating of the lighting systems leads to a high consumption of energy. Moreover, as new energy consumers such as electric vehicles become prevalent, patterns of energy consumption become more dynamic, which, in turn, leads to necessitating load management more often in time. Further, electricity generation will become more dynamic, as, recently, renewable energy sources are integrated into electricity grids. These trends result in multiple short-duration peaks and off-peaks of electricity demands and/or consumption. Thus, in future grids, dynamic load management will become increasingly challenging and critical. As known, the dynamic load management comprises, for example, techniques like dynamic demand and demand response; see for a more concrete explanation, for example, J. A. Short, D. G. Infield and L. L. Freris, “Stabilization of grid frequency through dynamic demand control,” IEEE Transactions on Power Systems, pp. 1284-1293, 2007 and/or A. Ipakchi and F. Albuyeh, “Grid of the future,” IEEE Power and Energy Magazine, pp. 52-62, 2009.
Dynamic demand involves passive shutting of devices to handle stress situations in the grid. Demand response, in turn, involves an explicit request to consumers to shut off devices. In either case, mechanisms for dynamic demand and demand response need to balance energy consumption to cater to dynamic variations in electricity generation/provision.
Electrical utility companies have been faced with a number of technical challenges in realizing load balancing and encouraging consumers to shed or shift load during periods of peak demand. Recently, a number of technologies have been developed with regard to sensing and monitoring, control and connectivity for enabling a greater flexibility in energy consumption across the grid. Thus, dynamic load management techniques like demand response or dynamic demand, for example, are the most commonly used techniques in electricity grids.
Lighting systems are attractive as controllable loads to enable dynamic load management. In lighting systems with controllable loads load reductions can be performed in a more predictable and substantial way. In general, lighting control systems are known and have been described in the literature.
For example, Lighting Research Program: Project 3.2 Energy Efficient Load-Shedding Lighting Technology Final Report, California Energy Commission Public Interest Energy Research Program, October 2005, CEC-500-2005-141-A6, describes that lamps or lighting devices are dimmed using load-shedding ballasts by a certain amount over a duration of time. The load-shedding ballast enables the lighting system to provide cost-effective electrical demand response. According to said publication, all lamps are dimmed under a load-shedding request and the approach is based on preset values and provides a static open loop control solution. However, such a solution can be acceptable to occupants for short time durations and small amounts of dimming. Longer durations of low dimming would, however, affect occupant comfort and productivity, as the user is not in the control loop. Furthermore, the solution may not be acceptable to all users, who may have different illumination requirements to the lighting system.
In U.S. Pat. No. 7,747,357 B2, for example, communication methods for transmitting and receiving load shedding messages are described. US 2010/0117620 A1, in turn, describes methods for automatically reducing power consumption based on load shedding requirements and set thresholds.
Although different lighting control methods are known, there is a need for new devices, methods and/or systems for smart lighting control.